Abstract (Proposal title: Neuroscience Gateway to Enable Dissemination of Computational and Data Processing Tools and Software.): This proposal presents a focused plan for expanding the capabilities of the Neuroscience Gateway (NSG) to meet the evolving needs of neuroscientists engaged in computationally intensive research. The NSG project began in 2012 with support from the NSF. Its initial goal was to catalyze progress in computational neuroscience by reducing technical and administrative barriers that neuroscientists faced in large scale modeling projects involving tools and software which require and run efficiently on high performance computing (HPC) resources. NSG's success is reflected in the facts that (1) its base of registered users has grown continually since it started operation in early 2013 (more than 800 at present), (2) every year the NSG team successfully acquires ever larger allocations of supercomputer time (recently more than 10,000,000 core hours/year) on academic HPC resources of the Extreme Science and Engineering Discovery (XSEDE ? that coordinates NSF supercomputer centers) program by writing proposals that go through an extremely competitive peer review process, and (3) it has contributed to large number of publications and Ph.D thesis. In recent years experimentalists, cognitive neuroscientists and others have begun using NSG for brain image data processing, data analysis and machine learning. NSG now provides over 20 tools on HPC resources for modeling, simulation and data processing. While NSG is currently well used by the neuroscience community, there is increasing interest from that community in applying it to a wider range of tasks than originally conceived. For example, some are trying to use it as an environment for dissemination of lab-developed tools, even though NSG is not suitable for that use because of delays from the batch queue wait times of production HPC resources, and lack of features and resources for an interactive, graphical, and collaborative environment needed for tool development, benchmarking and testing. ?Forced? use of NSG for development and dissemination makes NSG's operators a ?person-in-the-middle? bottleneck in the process. Another issue is that newly developed data processing tools require high throughput computing (HTC) usage mode, as opposed to HPC, but currently NSG does not provide access to compute resources suitable for HTC. Additionally, data processing workflows require features such as the ability to transfer large size data, process shared data, and visualize output results, which are not currently available on NSG. The work we propose will enhance NSG by adding the features that it needs to be a suitable and efficient dissemination environment for lab-developed neuroscience tools to the broader neuroscience community. This will allow tool developers to disseminate their lab-developed tools on NSG taking advantage of the current functionalities that are being well served on NSG for the last six years such as a growing user base, an easy user interface, an open environment, the ability to access and run jobs on powerful compute resources, availability of free supercomputer time, a well-established training and outreach program, and a functioning user support system. All of these well-functioning features of NSG will make it an ideal environment for dissemination and use of lab-developed computational and data processing neuroscience tools.